Polymers for intraocular lenses

ABSTRACT

The present invention provides optic portions, intraocular lenses, and polymers for use in manufacturing optic portions and intraocular lenses. The optic portions include a polymer that comprises (a) one or more alkoxyalkyl methacrylate monomers and/or one or more alkoxyalkyl acrylate monomers that are incorporated in the polymer; (b) one or more hydroxyalkyl methacrylate monomers and/or one or more hydroxyalkyl acrylate monomers that are incorporated in the polymer; and (c) optionally, one or more crosslinking agents that are incorporated in the polymer.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a divisional of U.S. application Ser. No.11/402,642, filed Apr. 12, 2006, which claims priority benefit under 35U.S.C. 119(e) U.S. Application Provisional Application No. 60/671,002,filed Apr. 13, 2005, incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to polymers for use in making optic portions ofintraocular lenses and intraocular lenses. More specifically, theinvention relates to polymers formed from one or more alkoxyalkylacrylate and/or an alkoxyalkyl methacrylate monomers and a hydrophilicmonomer or monomers such as 2-hydroxyethyl methacrylate (HEMA). Theinvention also relates to intraocular lenses made from the polymers, andmethods of making such lenses.

BACKGROUND OF THE INVENTION

Various types of intraocular lenses (IOLs) are known. For example, bothone-piece intraocular lenses and composite intraocular lens havingmultiple pieces are known. A one-piece intraocular lens is one whereboth optic and non-optic portions are made from one material. Thenon-optic portions of IOLs are referred to as haptic portions, and areused for attachment purposes. Two general designs for the haptics are a“plate-type” and a “C-haptic” type, both of which may have a variety ofshapes. A plate design is shown in FIGS. 1A and 1B. A “C” design isshown in FIGS. 2A and 2B. These Figures are discussed in greater detailbelow.

IOLs with mechanically-attached haptics are lenses where theoptic-portion and the haptic-portion are made separately, usually fromdifferent materials, and attached. For example, the lens portion can bemade of a hydrogel or silicone-based material and the C-shape hapticsfrom a rigid material like poly(methyl methacrylate) (p-MMA),polyvinylidene fluoride (PVDF), and polysulfones. The p-MMA haptics maybe attached to the optic portion using holes drilled into the opticportion.

Although traditional hydrophobic intraocular lenses are made from p-MMA,they are not easily foldable and require a relatively large incision forinsertion. To make hydrophobic materials foldable, rubber-likematerials, such as silicone derivatives, have been included in the rigidpolymer matrix or materials consisting primarily of silicone derivativeshave been used. Although the softness of a primarily silicone materialis ideal for folding prior to insertion, when the lens and its hapticsunfold in the eye, the almost gel-like softness of the lens makes itdifficult for a surgeon to properly position the lens in the eye.Furthermore, the silicone lens often does not provide sufficientrigidity for the lens after insertion and the combination of deformationfrom compressive forces along with lens movement can produce lensdistortion and compromise the optical integrity of the lens.

Because of its inherent properties, p-hydroxyethyl methacrylate (ahomopolymer of HEMA) has been used as a foldable material forintraocular lenses. However, the low refractive index of p-HEMA, whenhydrated, leads to limitations in the optical center design and acompromise between its folding ability and its optical requirements.

One of the limitations of one-piece p-HEMA hydrogel lenses has been thatthe haptic portion lacks the desired modulus and can, therefore,compromise lens positioning. To address this issue, polymer materialshave been combined to give a soft, foldable intraocular composite lenssuch as p-HEMA or other soft acrylic material for the optic zone, and arigid structure around the outside of the lens, made from a hard plasticsuch as p-MMA. See U.S. Pat. No. 4,718,906 and U.S. Pat. No. 5,326,506,both hereby incorporated by reference in their entireties, whichdescribe composite intraocular lenses. These multicomponent materialsare made by embedding one material in the other, by concurrent extrusionprocesses, by solidifying the hard material about the soft material, orby forming an interpenetrating network of the rigid component into apreformed hydrophilic core.

IOLs made from hydrophilic materials (hydrogels) have shown appropriatebiocompatibility in the eye capsule. The most common hydrophilic IOLmaterials range in water content between 24 and 28%. This water levelimparts the right range of mechanical properties that allow lenses to beeasily folded, placed in small diameter injectors, and introduced intothe capsular bag through incision sizes at or below 1.5 mm.

On the other hand, hydrophobic materials (generally less than about 4%water), may have desirable mechanical properties for use inmanufacturing IOLs. Aside from mechanical properties, IOLs made fromhydrophobic materials may exhibit reduced lens opacification rates fromeither posterior chamber opacification (PCO) following cataract surgeryor due to calcium deposits in the lens matrix. For this reason, thedevelopment of new hydrophobic polymers with suitable properties such asfoldability, unfoldability, and refractive index is important as thesemay be used to manufacture new and improved IOLs.

U.S. Pat. No. 5,326,506, discloses a composite intraocular lensincluding a soft, pliable inner lens optic using rigid haptics. The lensoptic material is a low water content material such as a copolymer of2-HEMA and hydroxyhexyl methacrylate which has a high refractive indexdue to its low water content. The hard, yet foldable, P-MMA haptics, areattached by an interpenetrating network.

U.S. Pat. No. 4,764,169, hereby incorporated by reference in itsentirety, discloses a composite intraocular lens including a small, hardinner lens optic and a soft, pliable skirt surrounding the lens optic.The lens optic material is a relatively hard material such as P-MMA,polysulfone, or polycarbonate. The soft, pliable skirt is a silicone,hydrogel, or like material.

Although significant strides have been made in the area of materials foruse in the manufacture of IOLs, novel polymeric materials with improvedproperties are still needed for use in manufacturing IOLs with improvedmechanical and optical properties.

SUMMARY OF THE INVENTION

The invention provides optic portions, intraocular lenses, polymers, andmethods for making polymers, optic portions, and intraocular lenses.

In one aspect the invention provides an optic portion of an intraocularlens, The optic portion includes a polymer that comprises, consists of,or consists essentially of:

-   -   (a) one or more alkoxyalkyl methacrylate monomers and/or one or        more alkoxyalkyl acrylate monomers that are incorporated in the        polymer;    -   (b) one or more hydroxyalkyl methacrylate monomers and/or one or        more hydroxyalkyl acrylate monomers that are incorporated in the        polymer; and    -   (c) optionally, one or more crosslinking agents that are        incorporated in the polymer. In some embodiments, the total        combined weight of the one or more alkoxyalkyl methacrylate        monomers and the one or more alkoxyalkyl acrylate monomers        ranges from 75 percent to 99 percent based on the total weight        of the dry polymer, and the total combined weight of the one or        more hydroxyalkyl methacrylate monomers and the one or more        hydroxyalkyl acrylate monomers ranges from 1 percent to 25        percent based on the total weight of the dry polymer.

In some embodiments, the invention provides an intraocular lens thatincludes an optic portion. In some such embodiments, the intraocularlens further includes one or more haptic portion. In some suchembodiments, the optic portion and the haptic portion are made of thesame polymer. In other embodiments, the optic portion and the hapticportion are made of different materials. In some embodiments, the opticportion and the one or more haptic portions are part of a one pieceintraocular lens. In other embodiments, the optic portion and the one ormore haptic portions form a multiple piece intraocular lens. In stillother embodiments, the intraocular lens further includes a polymer thatsurrounds the optic portion and is not the same as the polymer of theoptic portion.

In other embodiments of the optic portion and the intraocular lens, theone or more alkoxyalkyl methacrylate monomers have the formulaR₁—O—R₂-MA prior to being incorporated in the polymer, and the one ormore alkoxyalkyl acrylate monomers have the formula, R₃—O—R₄-A prior tobeing incorporated in the polymer, wherein MA is methacrylate, A isacrylate, and R₁, R₂, R₃, and R₄ are independently selected from alkylgroups having from 1 to 5 carbon atoms. In some such embodiments, R₁ andR₃ have from 1 to 3 carbon atoms, and R₂ and R₄ have 2 or 3 carbonatoms. In other such embodiments, R₁ and R₃ have 2 carbon atoms, and R₂and R₄ have 2 carbon atoms. In some such embodiments, the polymer of theoptic portion comprises incorporated ethoxyethyl methacrylate. In somesuch embodiments, the polymer of the optic portion comprisesincorporated ethoxyethyl methacrylate, and the total weight of theethoxyethyl methacrylate ranges from 80 percent to 98 percent, and insome embodiments, from 86 to 98 percent, based on the total weight ofthe dry polymer of the optic portion.

In other embodiments of the optic portion and the intraocular lens, theone or more hydroxyalkyl methacrylate monomers have the formula HO—R₅-MAprior to being incorporated in the polymer, and the one or morehydroxyalkyl acrylate monomers have the formula, HO—R₆-A prior to beingincorporated in the polymer, wherein MA is methacrylate, A is acrylate,and R₅ and R₆ are independently selected from alkyl groups having from 1to 4 carbon atoms. In some such embodiments, R₅ and R₆ have from 2 to 3carbon atoms. In other such embodiments, R₅ and R₆ have 2 carbon atoms.In some such embodiments, the polymer of the optic portion comprisesincorporated 2-hydroxyethyl methacrylate. In some such embodiments. thepolymer of the optic portion comprises incorporated 2-hydroxyethylmethacrylate, and the total weight of the 2-hydroxyethyl methacrylateranges from 1 percent to 20 percent, and in some embodiments, from 1percent to 12 percent, based on the total weight of the dry polymer ofthe optic portion.

In some embodiments, the polymer of the optic portion comprises, the oneor more crosslinking agents that are incorporated in the polymer. Insome such embodiments, at least one of the one or more crosslinkingagents is a di-functional crosslinking agent prior to incorporation inthe polymer. In some embodiments, the di-functional crosslinking agentis selected from ethylene glycol dimethacrylate prior to beingincorporated in the polymer or tetraethylene glycol dimethacrylate priorto being incorporated in the polymer. In some such embodiments, thepolymer of the optic portion comprises incorporated ethylene glycoldimethacrylate, and the total weight of the ethylene glycoldimethacrylate ranges from 0.05 percent to 0.5 percent, and in someembodiments, from 0.08 percent to 0.25 percent or from 0.1 percent to0.2 percent, based on the total weight of the dry polymer of the opticportion. In some embodiments, the at least one of the one or morecrosslinking agents is a multi-functional crosslinking agent prior toincorporation in the polymer. In some such embodiments, themulti-functional crosslinking agent is selected from trimethylol propanetrimethacrylate or trimethylol propane triacrylate prior to beingincorporated in the polymer. the polymer of the optic portion comprisesincorporated trimethylol propane trimethacrylate and/or trimethylolpropane triacrylate, and the total combined weight of the trimethylolpropane trimethacrylate and the trimethylol propane triacrylate rangesfrom 0.3 percent to 1.5 percent, and in some embodiments from 0.45percent to 1.2 percent or from 0.5 to 1.0 percent, based on the totalweight of the dry polymer of the optic portion.

In some embodiments, the polymer of the optic portion further includeswater.

In some embodiments, the polymer of the optic portion further includesone or more ultraviolet absorbing compounds and/or one or moreultraviolet absorbing monomer that is incorporated in the polymer ofoptic portion.

In some embodiments, the polymer of the optic portion, comprises,consists of, or consists essentially of:

-   -   (a) an incorporated alkoxyalkyl methacrylate in an amount of        from 87 percent to 98 percent by weight based on the total        weight of the dry polymer;    -   (b) an incorporated hydroxyalkyl methacrylate in an amount of        from 1.5 percent to 12 percent by weight based on the total        weight of the dry polymer;    -   (c) an incorporated di-functional methacrylate and/or        di-functional acrylate crosslinking agent in an amount ranging        from 0.085 percent to 0.2 percent based on the total weight of        the dry polymer;    -   (d) an incorporated multi-functional methacrylate and/or        multifunctional acrylate crosslinking agent in an amount ranging        from 0.4 percent to 1 percent based on the total weight of the        dry polymer; and    -   (e) optionally one or more additional ingredients selected from        water, a ultraviolet absorbing compound or monomer, a colorant,        or an antioxidant. In some such embodiments, the alkoxyalkyl        methacrylate is ethoxyethyl methacrylate, the hydroxyalkyl        methacrylate is 2-hydroxyethyl methacrylate, the di-functional        methacrylate and/or acrylate crosslinking agent is ethylene        glycol dimethacrylate, and the multi-functional methacrylate        and/or acrylate crosslinking agent is trimethylol propane        trimethacrylate.

In some embodiments, the glass transition temperature of the polymer ofthe optic portion is below about 35° C. whereas in other embodiments,the glass transition temperature is below about 30° C. or is below about25° C. In some such embodiments, the glass transition temperature of thepolymer of the optic portion is from about −25° C. to about 35° C., 30°C., or 25° C., and in other such embodiments is from about from about−5° C. to about 15° C., 20° C., or 25° C.

In some embodiments, the polymer of the optic portion has a refractiveindex of 1.40 or higher. In some such embodiments, the refractive indexis 1.46 or higher whereas in other such embodiments the refractive indexis 1.48 or higher.

In some embodiments, the polymer of the optic portion includes water,and the equilibrium water content is less than or about 5 percent basedon the weight of the polymer after it is hydrated. In some suchembodiments, the equilibrium water content ranges from 2 percent to 4.5percent based on the weight of the polymer after it is hydrated, whereasin other embodiments this ranges from 2.3 to 4.2 percent.

In some embodiments, the polymers of the invention include substantiallyno aromatic polymer, and in some embodiments includes less than 2percent, less than 1 percent, less than 0.5 percent, less than 0.25percent, less than 0.1 percent, less than 0.05 percent, or less than0.005 percent of any incorporated aromatic polymer based on the dryweight of the polymer.

In another aspect, the invention provides a polymer. The polymercomprises, consists of, or consists essentially of:

-   -   (a) one or more alkoxyalkyl methacrylate monomers and/or one or        more alkoxyalkyl acrylate monomers that are incorporated in the        polymer;    -   (b) one or more hydroxyalkyl methacrylate monomers and/or one or        more hydroxyalkyl acrylate monomers that are incorporated in the        polymer; and    -   (c) optionally, one or more crosslinking agents that are        incorporated in the polymer. In some embodiments, the total        combined weight of the one or more alkoxyalkyl methacrylate        monomers and the one or more alkoxyalkyl acrylate monomers        ranges from 75 percent to 99 percent based on the total weight        of the dry polymer, and the total combined weight of the one or        more hydroxyalkyl methacrylate monomers and the one or more        hydroxyalkyl acrylate monomers ranges from 1 percent to 25        percent based on the total weight of the dry polymer.

In some embodiments of the polymer, the one or more alkoxyalkylmethacrylate monomers have the formula R₁—O—R₂-MA prior to beingincorporated in the polymer, and the one or more alkoxyalkyl acrylatemonomers have the formula, R₃—O—R₄-A prior to being incorporated in thepolymer, wherein MA is methacrylate, A is acrylate, and R₁, R₂, R₃, andR₄ are independently selected from alkyl groups having from 1 to 5carbon atoms. In some such embodiments, R₁ and R₃ have from 1 to 3carbon atoms, and R₂ and R₄ have 2 or 3 carbon atoms. In some suchembodiments, R₁ and R₃ have 2 carbon atoms, and R₂ and R₄ have 2 carbonatoms.

In some such embodiments, the polymer includes incorporated ethoxyethylmethacrylate. In some such embodiments, the polymer comprisesincorporated ethoxyethyl methacrylate, and the total weight of theethoxyethyl methacrylate ranges from 80 percent to 98 percent based onthe total weight of the dry polymer. In some such embodiments, thepolymer comprises incorporated ethoxyethyl methacrylate, and the totalweight of the ethoxyethyl methacrylate ranges from 86 percent to 98percent based on the total weight of the dry polymer.

In some embodiments of the polymer, the one or more hydroxyalkylmethacrylate monomers have the formula HO—R₅-MA prior to beingincorporated in the polymer, and the one or more hydroxyalkyl acrylatemonomers have the formula, HO—R₆-A prior to being incorporated in thepolymer, wherein MA is methacrylate, A is acrylate, and R₅ and R₆ areindependently selected from alkyl groups having from 1 to 4 carbonatoms. In some embodiments, R₅ and R₆ have from 2 to 3 carbon atoms. Insome embodiments, R₅ and R₆ have 2 carbon atoms. In some suchembodiments, the polymer includes incorporated ethoxyethyl methacrylate.In some embodiments, the total weight of the ethoxyethyl methacrylateranges from 80 percent to 98 percent based on the total weight of thedry polymer. In some embodiments, the total weight of the ethoxyethylmethacrylate ranges from 86 percent to 98 percent based on the totalweight of the dry polymer.

In some embodiments of the polymer, the one or more hydroxyalkylmethacrylate monomers have the formula HO—R₅-MA prior to beingincorporated in the polymer, and the one or more hydroxyalkyl acrylatemonomers have the formula, HO—R₆-A prior to being incorporated in thepolymer, wherein MA is methacrylate, A is acrylate, and R₅ and R₆ areindependently selected from alkyl groups having from 1 to 4 carbonatoms. In some such embodiments, R₅ and R₆ have from 2 to 3 carbonatoms, whereas in other embodiments, R₅ and R₆ have 2 carbon atoms. Insome such embodiments, the polymer comprises incorporated 2-hydroxyethylmethacrylate. In some such embodiments, the total weight of the2-hydroxyethyl methacrylate ranges from 1 percent to 20 percent based onthe total weight of the dry polymer. In other such embodiments, thetotal weight of the 2-hydroxyethyl methacrylate ranges from 1 percent to12 percent based on the total weight of the dry polymer.

In certain embodiments, the polymer includes the one or morecrosslinking agents that are incorporated into the polymer. In some suchembodiments, at least one of the one or more crosslinking agents is adi-functional crosslinking agent prior to incorporation in the polymer.In some such embodiments, the di-functional crosslinking agent isselected from ethylene glycol dimethacrylate prior to being incorporatedin the polymer or tetraethylene glycol dimethacrylate prior to beingincorporated in the polymer. In some embodiments, the polymer comprisesincorporated ethylene glycol dimethacrylate, and the total weight of theethylene glycol dimethacrylate ranges from 0.05 percent to 0.5 percentbased on the total weight of the dry polymer. In other such embodiments,the total weight of the ethylene glycol dimethacrylate ranges from 0.08percent to 0.25 percent based on the total weight of the dry polymer. Instill other such embodiments, the total weight of the ethylene glycoldimethacrylate ranges from 0.1 percent to 0.2 percent based on the totalweight of the dry polymer.

In other embodiments, the polymer includes the one or more crosslinkingagents, and at least one of the one or more crosslinking agents is amulti-functional crosslinking agent prior to incorporation in thepolymer. In some such embodiments, the multi-functional crosslinkingagent is selected from trimethylol propane trimethacrylate ortrimethylol propane triacrylate prior to being incorporated in thepolymer. In some such embodiments, the polymer comprises incorporatedtrimethylol propane trimethacrylate and/or trimethylol propanetriacrylate, and the total combined weight of the trimethylol propanetrimethacrylate and the trimethylol propane triacrylate ranges from 0.3percent to 1.5 percent based on the total weight of the dry polymer. Inother such embodiments, the polymer comprises incorporated trimethylolpropane trimethacrylate and/or trimethylol propane triacrylate, and thetotal combined weight of the trimethylol propane trimethacrylate and thetrimethylol propane triacrylate ranges from 0.45 percent to 1.2 percentbased on the total weight of the dry polymer. In still other suchembodiments, the polymer comprises incorporated trimethylol propanetrimethacrylate and/or trimethylol propane triacrylate, and the totalcombined weight of the trimethylol propane trimethacrylate and thetrimethylol propane triacrylate ranges from 0.5 percent to 1.0 percentbased on the total weight of the dry polymer.

In some embodiments, the polymer further includes water. In some suchembodiments, the equilibrium water content is less than or about 5percent based on the weight of the polymer after it is hydrated. Inother such embodiments, the equilibrium water content ranges from 2percent to 4.5 percent or from 2.3 to 4.2 percent based on the weight ofthe polymer after it is hydrated.

In other embodiments, the polymer of the further comprises one or moreultraviolet absorbing compounds and/or one or more ultraviolet absorbingmonomer that is incorporated in the polymer of optic portion.

In still another embodiment, the polymer comprises, consists of, orconsists essentially of:

-   -   (a) an incorporated alkoxyalkyl methacrylate in an amount of        from 87 percent to 98 percent by weight based on the total        weight of the dry polymer;    -   (b) an incorporated hydroxyalkyl methacrylate in an amount of        from 1.5 percent to 12 percent by weight based on the total        weight of the dry polymer;    -   (c) an incorporated di-functional methacrylate and/or        di-functional acrylate crosslinking agent in an amount ranging        from 0.085 percent to 0.2 percent based on the total weight of        the dry polymer;    -   (d) an incorporated multi-functional methacrylate and/or        multifunctional acrylate crosslinking agent in an amount ranging        from 0.4 percent to 1 percent based on the total weight of the        dry polymer; and    -   (e) optionally one or more additional ingredients selected from        water, a ultraviolet absorbing compound or monomer, a colorant,        or an antioxidant. In some such embodiments, the alkoxyalkyl        methacrylate is ethoxyethyl methacrylate, the hydroxyalkyl        methacrylate is 2-hydroxyethyl methacrylate, the di-functional        methacrylate and/or acrylate crosslinking agent is ethylene        glycol dimethacrylate, and the multi-functional methacrylate        and/or acrylate crosslinking agent is trimethylol propane        trimethacrylate.

In certain embodiments, the polymer includes substantially no aromaticpolymer.

In another aspect, the invention provides a method for manufacturing apolymer. The method includes:

-   -   (a) polymerizing a mixture to form the polymer, wherein the        mixture comprises, consists of, or consists essentially of:        -   (i) one or more alkoxyalkyl methacrylate monomers and/or one            or more alkoxyalkyl acrylate monomers;        -   (ii) one or more hydroxyalkyl methacrylate monomers and/or            one or more hydroxyalkyl acrylate monomers;        -   (iii) optionally, one or more crosslinking agents; and        -   (iv) optionally, one or more initiator.            In some embodiments, the total combined weight of the one or            more alkoxyalkyl methacrylate monomers and the one or more            alkoxyalkyl acrylate monomers in the mixture ranges from 75            percent to 99 percent based on the total combined weight of            the one or more alkoxyalkyl methacrylate monomers, the one            or more alkoxyalkyl acrylate monomers, the one or more            hydroxyalkyl methacrylate monomers, the one or more            hydroxyalkyl acrylate monomers, and the one or more            crosslinking agents in the mixture, and the total combined            weight of the one or more hydroxyalkyl methacrylate monomers            and the one or more hydroxyalkyl acrylate monomers in the            mixture ranges from 1 percent to 25 percent based on the            total combined weight of the one or more alkoxyalkyl            methacrylate monomers, the one or more alkoxyalkyl acrylate            monomers, the one or more hydroxyalkyl methacrylate            monomers, the one or more hydroxyalkyl acrylate monomers,            and the one or more crosslinking agents in the mixture.

In some embodiments of the method for manufacturing a polymer, themixture is polymerized in a mold. In some embodiments, the methodfurther includes forming an optic portion of an intraocular lens fromthe polymer. In some such embodiments, the method further includesforming an intraocular lens from the optic portion. In some embodiments,the method for manufacturing a polymer further includes forming anintraocular lens from the polymer.

In some embodiments of the method for manufacturing a polymer, the oneor more alkoxyalkyl methacrylate monomers have the formula R₁—O—R₂-MA,and the one or more alkoxyalkyl acrylate monomers have the formula,R₃—O—R₄-A, wherein MA is methacrylate, A is acrylate, and R₁, R₂, R₃,and R₄ are independently selected from alkyl groups having from 1 to 5carbon atoms. In some such embodiments, R₁ and R₃ have from 1 to 3carbon atoms, and R₂ and R₄ have 2 or 3 carbon atoms. In some suchembodiments, R₁ and R₃ have 2 carbon atoms, and R₂ and R₄ have 2 carbonatoms. In some embodiments, the mixture comprises ethoxyethylmethacrylate. In some such embodiments, the mixture comprisesethoxyethyl methacrylate, and the total weight of the ethoxyethylmethacrylate in the mixture ranges from 80 percent to 98 percent basedon the total combined weight of the one or more alkoxyalkyl methacrylatemonomers, the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture. In still other such embodiments, the mixture comprisesethoxyethyl methacrylate, and the total weight of the ethoxyethylmethacrylate in the mixture ranges from 86 percent to 98 percent basedon the total combined weight of the one or more alkoxyalkyl methacrylatemonomers, the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture.

In some embodiments of the method for manufacturing a polymer, the oneor more hydroxyalkyl methacrylate monomers have the formula HO—R₅-MA,and the one or more hydroxyalkyl acrylate monomers have the formula,HO—R₆-A, wherein MA is methacrylate, A is acrylate, and R₅ and R₆ areindependently selected from alkyl groups having from 1 to 4 carbonatoms. In some such embodiments, R₅ and R₆ have from 2 to 3 carbonatoms. In still other such embodiments, R₅ and R₆ have 2 carbon atoms.In some such embodiments, the mixture comprises 2-hydroxyethylmethacrylate. In still other such embodiments, the mixture comprises2-hydroxyethyl methacrylate, and the total combined weight of the2-hydroxyethyl methacrylate in the mixture ranges from 1 percent to 20percent based on the total combined weight of the one or morealkoxyalkyl methacrylate monomers, the one or more alkoxyalkyl acrylatemonomers, the one or more hydroxyalkyl methacrylate monomers, the one ormore hydroxyalkyl acrylate monomers, and the one or more crosslinkingagents in the mixture. In some such embodiments, the mixture comprises2-hydroxyethyl methacrylate, and the total weight of the 2-hydroxyethylmethacrylate in the mixture ranges from 1 percent to 12 percent based onthe total combined weight of the one or more alkoxyalkyl methacrylatemonomers, the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture.

In some embodiments of the method for manufacturing a polymer, themixture comprises, the one or more crosslinking agents. In some suchembodiments, at least one of the one or more crosslinking agents is adi-functional crosslinking agent. In some such embodiments, thedi-functional crosslinking agent is selected from ethylene glycoldimethacrylate or tetraethylene glycol dimethacrylate. In some suchembodiments, the mixture comprises ethylene glycol dimethacrylate, andthe total weight of the ethylene glycol dimethacrylate in the mixtureranges from 0.05 percent to 0.5 percent based on the total combinedweight of the one or more alkoxyalkyl methacrylate monomers, the one ormore alkoxyalkyl acrylate monomers, the one or more hydroxyalkylmethacrylate monomers, the one or more hydroxyalkyl acrylate monomers,and the one or more crosslinking agents in the mixture. In some suchembodiments, the mixture comprises ethylene glycol dimethacrylate, andthe total weight of the ethylene glycol dimethacrylate in the mixtureranges from 0.08 percent to 0.25 percent based on the total combinedweight of the one or more alkoxyalkyl methacrylate monomers, the one ormore alkoxyalkyl acrylate monomers, the one or more hydroxyalkylmethacrylate monomers, the one or more hydroxyalkyl acrylate monomers,and the one or more crosslinking agents in the mixture. In still othersuch embodiments, the mixture comprises ethylene glycol dimethacrylate,and the total weight of the ethylene glycol dimethacrylate ranges from0.1 percent to 0.2 percent based on the total combined weight of the oneor more alkoxyalkyl methacrylate monomers, the one or more alkoxyalkylacrylate monomers, the one or more hydroxyalkyl methacrylate monomers,the one or more hydroxyalkyl acrylate monomers, and the one or morecrosslinking agents in the mixture. In some embodiments in which themixture comprising one or more crosslinking agents, at least one of theone or more crosslinking agents is a multi-functional crosslinkingagent. In some such embodiments, the multi-functional crosslinking agentis selected from trimethylol propane trimethacrylate or trimethylolpropane triacrylate. In some other such embodiments, the mixturecomprises trimethylol propane trimethacrylate and/or trimethylol propanetriacrylate, and the total combined weight of the trimethylol propanetrimethacrylate and the trimethylol propane triacrylate in the mixtureranges from 0.3 percent to 1.5 percent based on the total combinedweight of the one or more alkoxyalkyl methacrylate monomers, the one ormore alkoxyalkyl acrylate monomers, the one or more hydroxyalkylmethacrylate monomers, the one or more hydroxyalkyl acrylate monomers,and the one or more crosslinking agents in the mixture. In certain suchembodiments, the mixture comprises trimethylol propane trimethacrylateand/or trimethylol propane triacrylate, and the total combined weight ofthe trimethylol propane trimethacrylate and the trimethylol propanetriacrylate in the mixture ranges from 0.45 percent to 1.2 percent basedon the total combined weight of the one or more alkoxyalkyl methacrylatemonomers, the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture. In still other such embodiments, the mixture comprisestrimethylol propane trimethacrylate and/or trimethylol propanetriacrylate, and the total combined weight of the trimethylol propanetrimethacrylate and the trimethylol propane triacrylate in the mixtureranges from 0.5 percent to 1.0 percent based on the total combinedweight of the one or more alkoxyalkyl methacrylate monomers, the one ormore alkoxyalkyl acrylate monomers, the one or more hydroxyalkylmethacrylate monomers, the one or more hydroxyalkyl acrylate monomers,and the one or more crosslinking agents in the mixture.

In some embodiments of the method for manufacturing a polymer, themixture further comprises one or more ultraviolet absorbing compoundsand/or one or more ultraviolet absorbing monomer.

In some embodiments of the method for manufacturing a polymer, themixture comprises, consists of, or consists essentially of:

-   -   (a) an alkoxyalkyl methacrylate, wherein the alkoxyalkyl        methacrylate is present in the mixture in an amount of from 87        percent to 98 percent by weight based on the total combined        weight of the one or more alkoxyalkyl methacrylate monomers, the        one or more alkoxyalkyl acrylate monomers, the one or more        hydroxyalkyl methacrylate monomers, the one or more hydroxyalkyl        acrylate monomers, and the one or more crosslinking agents in        the mixture;    -   (b) a hydroxyalkyl methacrylate, wherein the hydroxyalkyl        methacrylate is present in the mixture in an amount of from 1.5        percent to 12 percent by weight based on the total combined        weight of the one or more alkoxyalkyl methacrylate monomers, the        one or more alkoxyalkyl acrylate monomers, the one or more        hydroxyalkyl methacrylate monomers, the one or more hydroxyalkyl        acrylate monomers, and the one or more crosslinking agents in        the mixture;    -   (c) a di-functional methacrylate and/or di-functional acrylate        crosslinking agent, wherein the combined weight of the        di-functional methacrylate and/or the di-functional acrylate        crosslinking agent in the mixture ranges from 0.085 percent to        0.2 percent based on the total combined weight of the one or        more alkoxyalkyl methacrylate monomers, the one or more        alkoxyalkyl acrylate monomers, the one or more hydroxyalkyl        methacrylate monomers, the one or more hydroxyalkyl acrylate        monomers, and the one or more crosslinking agents in the        mixture;    -   (d) a multi-functional methacrylate and/or multifunctional        acrylate crosslinking agent, wherein the combined weight of the        multi-functional methacrylate and/or the multi-functional        acrylate crosslinking agent in the mixture ranges from 0.4        percent to 1 percent based on the total combined weight of the        one or more alkoxyalkyl methacrylate monomers, the one or more        alkoxyalkyl acrylate monomers, the one or more hydroxyalkyl        methacrylate monomers, the one or more hydroxyalkyl acrylate        monomers, and the one or more crosslinking agents in the        mixture; and    -   (e) optionally one or more additional ingredients selected from        an initiator, an ultraviolet absorbing compound or monomer, a        colorant, or an antioxidant. In some such embodiments, the        alkoxyalkyl methacrylate is ethoxyethyl methacrylate, the        hydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate, the        di-functional methacrylate and/or acrylate crosslinking agent is        ethylene glycol dimethacrylate, and the multi-functional        methacrylate and/or acrylate crosslinking agent is trimethylol        propane trimethacrylate.

In some embodiments of the method for manufacturing a polymer, theequilibrium water content is less than or about 5 percent based on theweight of the polymer after it is hydrated. In some such embodiments,the equilibrium water content ranges from 2 percent to 4.5 percent basedon the weight of the polymer after it is hydrated. In still other suchembodiments, the equilibrium water content ranges from 2.3 percent to4.2 percent based on the weight of the polymer after it is hydrated.

In some embodiments of the method for manufacturing a polymer, themixture contains substantially no aromatic polymer. In still other suchembodiments, the mixture comprises less than 2 percent by weight of anyaromatic component.

In some embodiments of the method for manufacturing a polymer, themethod further includes attaching one or more haptic portions to anoptic portion formed from the polymer.

The present invention also provides a method for modifying, correctingor improving an individual's eyesight that includes inserting any of thepresent intraocular lenses into an eye of a subject. This method canalso include folding the intraocular lens prior to inserting theintraocular lens into the eye and allowing the intraocular lens tounfold after it is inserted into the eye. These methods can also includeremoving a lens, either natural or artificial, from the eye of thesubject prior to inserting the intraocular lens.

Further objects, features, and advantages of the present invention willbecome apparent from the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of an intraocular lens having a plate-shapedhaptic.

FIG. 1B is a side view of the intraocular lens having a plate-shapedhaptic shown in FIG. 1A.

FIG. 2A is a top view of an intraocular lens having a C-shaped haptic.

FIG. 2B is a side view of the intraocular lens having a C-shaped hapticshown in FIG. 2A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides polymer compositions that areparticularly useful for manufacturing optic portions intraocular lensesand intraocular lenses. A polymer for the purposes of the presentinvention means a polymer formed from one or more differentpolymerizable monomers and may include crosslinkers and other additivesas described herein. These polymers have as their primary components,i.e. the primary monomer present in the polymer by weight, a combinationof one or more alkoxyalkyl methacrylate monomers and/or one or morealkoxyalkyl acrylate monomers. For purposes of the present invention,all of the one or more alkoxyalkyl methacrylate monomers, which can bethe same or different, and/or the one or more alkoxyalkyl acrylatemonomers, which can also be the same or different, are considered assingle component of the present polymers.

Alkoxyalkyl methacrylate monomers can be represented by the formulaR₁—O—R₂-MA where R₁ and R₂ are alkyl groups and “MA” is methacrylate.Alkoxyalkyl acrylate monomers can be represented by the formulaR₃—O—R₄-A where R₃ and R₄ are alkyl groups and “A” is acrylate. Bothalkoxyalkyl methacrylates and alkoxyalkyl acrylates are ester-containingmonomer compounds as will be recognized by those skilled in the art. Insome embodiments, R₁ to R₄ can be independently selected from alkylgroups having 1 to 5 carbon atoms and in some embodiments 1, 2, 3, 4, or5 carbon atoms. With respect to R₂, it will be understood that the alkylgroup is bonded to the O of the R₁—O group and is also bonded to the Oatom of the MA group. Similarly, with respect to R₄, it will beunderstood that the alkyl group is bonded to the O of the R₃—O group andis also bonded to the O atom of the A group. Alkyl groups that may beused in accordance with the invention include straight chain alkylgroups, including but not limited to methyl, ethyl, propyl, butyl, andpentyl groups. Alkyl groups may also include branched chain isomers ofstraight chain alkyl groups including, but not limited to, thefollowing, which are provided by way of example only: —CH(CH₃)₂,—CH(CH₃)(CH₂CH₃), —CH(CH₂CH₃)₂, —C(CH₃)₃, and the like. In someembodiments, the alkoxyalkyl methacrylate or alkoxyalkyl acrylate isselected where R₁, to R₄ have 1, 2, 3, or 4 carbon atoms. Examples ofsome specific alkoxyalkyl methacrylate and alkoxyalkyl acrylate monomersuseful for forming the polymers of the invention include, but are notlimited to, methoxyethyl methacrylate, ethoxyethyl methacrylate,propoxyethyl methacrylate, butoxymethyl methacrylate, methoxypropylmethacrylate, ethoxypropyl methacrylate, propoxypropyl methacrylate,butoxypropyl methacrylate, methoxybutyl methacrylate, ethoxybutylmethacrylate, propoxybutyl methacrylate, butoxybutyl methacrylate,methoxyethyl acrylate, ethoxyethyl acrylate, propoxyethyl acrylate,butoxymethyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate,propoxypropyl acrylate, butoxypropyl acrylate, methoxybutyl acrylate,ethoxybutyl acrylate, propoxybutyl acrylate, and butoxybutyl acrylate.In some embodiments, the polymer includes ethoxyethyl methacrylate(EOEMA).

The present polymers also include one or more hydrophilic monomer.Examples of such hydrophilic monomers include hydroxyalkyl methacrylatesand hydroxyalkyl acrylates. Hydroxyalkyl methacrylates may berepresented by the formula HO—R₅-MA where R₅ is an alkyl group having 1to 4 carbon atoms and “MA” is methacrylate. Hydroxyalkyl acrylates maybe represented by the formula HO—R₆-A where R₆ is an alkyl group havingfrom 1 to 4 carbon atoms and “A” is acrylate. With respect to R₅, itwill be understood that the alkyl group is bonded to the O of the HOgroup and is also bonded to the O atom of the MA group. Similarly, withrespect to R₆, it will be understood that the alkyl group is bonded tothe O of the HO group and is also bonded to the O atom of the A group.Examples of hydroxyalkyl methacrylates and hydroxyalkyl acrylatesinclude, but not limited to 2-hydroxyethyl methacrylate, 3-hydroxypropylmethacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate,3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxyethylacrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate,2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, and 4-hydroxybutylacrylate. In some embodiments, the polymer includes 2-hydroxyethylmethacrylate (HEMA).

The polymers of the present invention include the alkoxyalkylmethacrylate and/or alkoxyalkyl acrylate monomers as the major componentand the hydrophilic monomer(s) as the minor component.

As used herein, the term “polymer” refers to a composition that isformed by polymerizing one or more different monomers. The term“polymer” thus includes “homopolymers” formed from only one type ofmonomer, “copolymers” which are formed from two or more differentmonomers, “terpolymers” formed from at least three different monomers,and any polymer that is formed from at least one type of monomer and maybe formed from one, two, three, four, or more different monomers.

Other monomers may be present in the polymers of the present inventionincluding, but not limited to, alkoxyalkoxyalkyl methacrylates such as,but not limited to, ethoxyethoxyethyl methacrylate; alkoxyalkoxyalkylacrylates, such as, but not limited to ethoxyethoxyethyl acrylate; alkylmethacrylate monomers; and combinations thereof with specific examplesof alkyl methacrylate monomers being C₁ alkyl to C₁₅ alkyl methacrylatemonomers such as, but not limited to, methyl methacrylate, ethylmethacrylate, propyl methacrylate, butyl methacrylate, hexylmethacrylate, lauryl methacrylate, and combinations thereof. Someembodiments of the invention do not include any alkoxyalkoxyalkylmethacrylate or any alkoxyalkoxyalkyl methacrylate.

In the present polymers, the total quantity of the one or morealkoxyalkyl methacrylate and/or the one or more alkoxyalkyl acrylatemonomers will make up the majority of the polymer. For example, in someembodiments, the total quantity of the combined amounts of anyalkoxyalkyl methacrylate and/or alkoxyalkyl acrylate monomer(s) isgreater than about 80 percent by weight based on the total weight of thepolymer. In some such embodiments, the total quantity of the combinedamounts of any alkoxyalkyl methacrylate and/or alkoxyalkyl acrylatemonomer(s) is greater than about 85 percent, greater than about 90percent, or greater than about 95 percent by weight based on the totalweight of the polymer. In still other embodiments, the total quantity ofthe combined amounts of any alkoxyalkyl methacrylate and/or alkoxyalkylacrylate monomer(s) is greater than about 96, 97, or 98 percent byweight based on the total weight of the polymer.

The present polymers can also include various other components thatimprove the characteristics of the polymer. Non-limiting examples ofother components include one or more ultraviolet absorbing compounds,one or more crosslinking agents, such as, but not limited to,incorporated ethylene glycol dimethacrylate (EGDMA), incorporatedtetraethylene glycol dimethacrylate (TEGDMA), incorporated trimethylolpropane trimethacrylate (TMPTMA) or the analogous triacrylate, one ormore colorants, and combinations thereof. Those skilled in the art willrecognize that various known cross-linking agents may be used in thepolymers and methods in accordance with the invention.

When a polymer is said to include a monomer such as ethoxyethylmethacrylate, it will be understood that this means that the ethoxyethylmethacrylate monomer has been reacted and incorporated into the polymer.

One exemplary polymeric composition contains about 87 percent to about99 percent of an alkoxyalkyl methacrylate and about 1 percent to about13 percent of a hydroxyalkyl methacrylate, with the balance of thepolymer being made up of other components, such as UV absorbers,initiation agents and/or crosslinking agents. Another exemplarycomposition contains about 88 percent to about 98 percent of analkoxyalkyl methacrylate and about 2 percent to about 12 percent of ahydroxyalkyl methacrylate with the balance of the polymer again beingmade up of other components. Another exemplary composition containsabout 90 percent to about 98 percent of an alkoxyalkyl methacrylate andabout 2 percent to about 10 percent of a hydroxyalkyl methacrylate withthe balance of the polymer again being made up of other components.Still other exemplary compositions contain about 92 percent to about 96percent of an alkoxyalkyl methacrylate and about 4 percent to about 8percent of a hydroxyalkyl methacrylate with the balance of the polymeragain being made up of other components. In some of these compositions,the alkoxyalkyl methacrylate may be ethoxyethyl methacrylate. In stillother such compositions, the hydroxyalkyl methacrylate is 2-hydroxyethylmethacrylate. As can be seen from these exemplary compositions, thepresent intraocular lens can have a range of material components andstill have the desired characteristics. The polymer compositions of thepresent invention generally include one or more crosslinking agent. Insome embodiments, the compositions includes one or more crosslinker withtwo polymerizable functionalities (a di-functional crosslinking agent).Examples of such crosslinking agents include, but are not limited toethylene glycol dimethacrylate (EGDMA) and tetraethylene glycoldimethacrylate (TEGDMA). Some embodiments also include a crosslinkingagent with three or more polymerizable functionalities (amulti-functional crosslinking agent). An example of a multi-functionalcrosslinking agent includes, but is not limited to, trimethylol propanetrimethacrylate (TMPTMA). The analogous acrylate crosslinking agents,for example, ethylene glycol diacrylate, tetraethylene glycoldiacrylate, and trimethylol propane triacrylate, may also be utilized inaccordance with the invention in place of any of their methacrylateanalogs or in combination with the methacrylate analogs. Someembodiments include two or more di-functional crosslinking agents. Stillother embodiments include both a di-functional crosslinking agent and amulti-functional crosslinking agent. Therefore, in some embodiments, thepolymer compositions include EGDMA and TMPTMA. In some such embodiments,the amount of EGDMA ranges from about 0.05 to about 0.5 or about 0.4percent by weight based on the weight of the dry polymer and the amountof the TMPTMA ranges from about 0.3 to about 1.5 percent by weight basedon the weight of the dry polymer. In some such embodiments, the amountof EGDMA ranges from about 0.08 to about 0.25 percent by weight based onthe weight of the dry polymer and the amount of the TMPTMA ranges fromabout 0.45 to about 1.2 percent by weight based on the weight of the drypolymer. In still other such embodiments, the amount of EGDMA rangesfrom about 0.1 to about 0.2 percent by weight based on the weight of thedry polymer and the amount of the TMPTMA ranges from about 0.5 to about1.0 percent by weight based on the weight of the dry polymer. In some ofembodiments, the polymer compositions of the present invention consistof or consist essentially of a polymer formed from an alkoxyalkylmethacrylate, a hydroxyalkyl methacrylate, and one or more crosslinkingagent. In some such embodiments, the polymer is formed from a monomersconsisting of ethoxyethyl methacrylate, 2-hydroxyethyl methacrylate,EGDMA, and TMPTMA. In some such embodiments, the ratio of the EGDMA tothe TMPTMA ranges from 1:4 to 1:6 and in some embodiments is about 1:5.In some such embodiments, the ratio of the EOEMA to HEMA used to makethe polymer ranges from 88:12 to 98:2. In embodiments, a polymer of theinvention comprises, consists essentially of, or consists of:

(a) An incorporated alkoxyalkyl methacrylate such as EOEMA in an amountof from 87 to 98 percent;

(b) An incorporated hydroxyalkyl methacrylate such as HEMA in an amountof from 1.5 to 12 percent;

(c) An incorporated di-functional methacrylate or acrylate crosslinkingagent such as EGDMA in an amount ranging from 0.085 to 0.2 percent;

(d) An incorporated multi-functional methacrylate or acrylatecrosslinking agent such as TMPTMA in an amount ranging from 0.4 to 1percent; and

(e) One or more optional other ingredients such as water, one or more UVabsorbing compound or monomer, a colorant, and an antioxidant.

In most embodiments, the present polymers will contain no, orsubstantially no, monomers that have aromatic constituents. Previously,aromatic monomers have been added to polymers in order to increase therefractive index of the polymer so as to make the polymer more suitablefor lens formation. However, aromatic monomers also increase thestiffness of the resulting polymer making any resulting lens made fromthe polymer more difficult to manipulate or fold without damaging thelens. The present polymers overcome this problem by balancing thephysical characteristics of the polymer used to make the lens.Accordingly, in some embodiments 10 percent, 5 percent, 2 percent, 1percent, 0.1 percent or less of the monomers used to make the presentpolymers will have aromatic constituents.

The polymers of the present invention generally have a water content ofless than or about 5 percent based on the weight of the polymer after itis fully equilibrated in water. In some embodiments, the polymers have awater content at equilibrium that ranges from at or about 2 percent toat or about 4.5 percent based on the weight of the polymer after it isfully equilibrated in water. In other embodiments, the water contentranges from about 2.3 percent to about 4.2 percent by weight of thepolymer after it is fully equilibrated with water.

The polymers of the present invention possess superior mechanical andoptical properties over other materials used to make IOLs. Thecombination of a hydrophilic monomer such as a hydroxyalkyl methacrylatewith a hydrophobic monomer such as an alkoxyalkyl methacrylate providesmaterials with higher levels of water than is possible withoutincorporation of the hydrophilic monomer. Therefore, the uniquecombination of materials provides polymers compositions that may be usedto prepare IOLs with improved folding and unfolding properties ascompared with acrylic rubbers. At the same time, the higher water levelsof the polymers of the invention provides increased hydrophilicity atthe lens surface thus providing improved biocompatibility.

The present polymers can be designed to have a wide range of physicalcharacteristics. In some instances, the present polymers can be designedto have glass transition temperatures below at or about 35° C., below ator about 30° C., below at or about 25° C., such as from at or about −25°C. to at or about 35° C., 30° C., or 25° C., from about −5° C. to about15° C., 20° C., or about 25° C. or from at or about 0° C. to at or about15° C. One skilled in the art will recognize that the lower the glasstransition temperature the more rubbery the polymer. As the presentpolymers have been designed to be used as intraocular lenses, they alsotypically have a high refractive index, which is generally above about1.40. Some of the present polymers can have a refractive index of 1.48or higher. Because the present polymers are hydrophobic, they can alsohave equilibrium water contents that are about 5 percent or less, forexample 3 percent, 2 percent, 1 percent or less. Due to their low watercontents, the present polymers are generally not considered hydrogelsand may be considered as hydrophobic. Generally, the present lenses alsohave advantageous properties compared to prior lenses because they havea comparable or higher refractive index than lenses containing siliconeor p-hydroxyethyl methacrylate and are more flexible, e.g., foldable,than hydrophobic lenses that include aromatic monomers to increase therefractive index of the resulting polymer.

The present invention also provides intraocular lenses made at leastpartially from the present polymers. Such intraocular lenses include anoptic portion and one or more haptic portions. Typically, the polymersof the invention will make up part or all of the optic portion of theintraocular lens. In some embodiments, the optic portion of the lenswill have a core made from one of the present polymers surrounded bydifferent polymer or material. Lenses in which the optic portion is madeup of at least partially of one of the present polymers will usuallyalso have a haptic portion. The haptic portion can also be made ofpolymer of the invention or can be made of a different material, forexample another polymer.

In some embodiments, the present intraocular lens is a one-piece lenshaving a soft, foldable central optic region and an outer peripheralregion (haptic-region) in which both regions are made of the samepolymer. In other embodiments, the optic and haptic regions can beformed from different types of polymers or materials, if desired. Somelenses can also have haptic portions that are made up of differentmaterials, for example where one or more haptic portions is made fromthe same material as the optic portion and other haptic portions aremade of materials other than a polymer of the invention. Multicomponentlenses can be made by embedding one material in the other, concurrentextrusion processes, solidifying the hard material about the softmaterial, or forming an interpenetrating network of the rigid componentinto a preformed hydrophobic core. In instances where one or more hapticportions are made from a different material than the optic portion ofthe lens, the haptic portion can be attached to the optic portion in anymanner known in the art, such as by drilling a hole or holes in theoptic portion and inserting the haptic portion.

The polymers of the present invention have been designed so that theyare capable of being folded so that the intraocular lens can be insertedinto the eye of an individual through a small incision. The hapticportion of the lens provides the required support for the lens in theeye after insertion and unfolding of the lens and tends to helpstabilize the position of the lens after insertion and the closure ofthe incision. The shape of the haptic portion design is not particularlylimited and can be any desired configuration, for example, either aplate type or graduated thickness spiral filaments, also known as aC-loop design.

FIGS. 1A, 1B, 2A, and 2B illustrate examples of intraocular lenses inaccordance with the present invention. The figures are for illustrativepurposes only and do not limit the scope of the invention. For instance,the intraocular lens can be any type of intraocular lens. In thefigures, 1 is the optic portion of the lens, 2 is the haptic portion,and 3 is a positioning hole. One skilled in the art of intraocularlenses understands the functions of these portions of the intraocularlens.

The optic portion 1 can be approximately 6 mm in diameter prior tohydration. The 6 mm diameter is fairly standard in the art, and isgenerally chosen to cover the pupil in its fully dilated state undernaturally occurring conditions. However, other sizes are possible andthe present invention is not limited to any particular diameter or sizeof intraocular lens. Furthermore, it is not necessary that the lensoptic portion be circular; it could also be oval, square, or any othershape as desired.

The intraocular lens can further include one or more non-optical hapticcomponents 2 extending away from the outermost peripheral surface of theoptic portion. The haptic components can be of any desired shape, forexample, graduated spiral filaments or flat plate sections and are usedto support the lens within the posterior chamber of the eye. Lenseshaving any desired design configuration can be fabricated. Further,although two types of haptic designs are shown in the figures, thehaptics can have configurations other than those illustrated. Should theintraocular lens include other components besides the optical and hapticportions, such other portions can be made of a polymer as are the hapticand optic portions, or if desired, another material.

The intraocular lenses of the invention may be inserted into the eye inknown manners. For example, the intraocular lens may be folded prior toinsertion into the eye by small, thin forceps of the type typically usedby ophthalmic surgeons. After the lens is in the targeted location, itis released to unfold. As is well known in the art, typically the lensthat is to be replaced is removed prior to insertion of the intraocularlens. The intraocular lens of the present invention can be made of agenerally physiologically inert soft polymeric material that is capableof providing a clear, transparent, refractive lens body even afterfolding and unfolding. In some embodiments, the foldable intraocularlens of the present invention can be inserted into any eye by injectionwhereby the mechanically compliant material is folded and forced througha small tube such as a 1 mm to 3 mm inner diameter tube.

The polymers of the invention can be prepared using conventionalpolymerization techniques known to those in the field of polymerchemistry. Crosslinkers, also referred to as crosslinking agents, may beemployed in the polymerization reaction. For example, any suitablecrosslinking di-functional, multi-functional monomer, or combination ofthese can be used in effective amounts to give the desired crosslinkingdensity. For example, in a concentration range of 0.4 to about 4percent, such as about 0.4 to about 3 percent, or in some embodimentsfrom 0.5 to 1.5 percent by weight, based on the weight of the polymer.Examples of suitable crosslinking agents include di-olefinic compoundssuch as ethylene glycol dimethacrylate (EGDMA) and tetraethylene glycoldimethacrylate (TEGDMA) and other cross-linking agents such astrimethylol propane trimethacrylate (TMPTMA) which include three or moreolefinic polymerizable functionalities. Generally, crosslinkers help toenhance the resulting polymer's dimensional stability.

Also, if desired an initiator can be used in the polymerization. Anyinitiator commonly used in the art, such as azo derivatives, like2,2-azobis (2,4-dimethylvaleronitrile) andpropanenitrile,2-methyl,2,2′-azobis, can be used. The initiator is usedin an amount effective for initiation purposes, and is generally presentfrom about 0.01 to 1.0 percent by weight, based on the weight of thepolymer.

The polymers of the present invention can also include additionalmonomers, such as, but not limited to, monomers that impart UVabsorption to the polymer. UV absorbing monomers are typically aromaticcompounds with olefinic functionality. The advantageous ultraviolet (UV)absorbing compounds can be added prior to polymerization forincorporation into the resultant polymer, as is well known in the art.The UV absorber should preferably be capable of polymerization into thelens matrix so as to be stable under physiological conditions. Anymonomer copolymerizable with the described monomers can optionally beused, so long as such does not materially, adversely effect the basiccharacteristics of the intraocular lens. Examples of useful additionalmonomers that can used are described in U.S. Pat. No. 5,326,506, herebyincorporated by reference, directed to a composite intraocular lens.Such optional additional monomers, preferably are present in a totalamount of not more than 10 weight percent, generally less than 5 weightpercent, based on the total weight of the polymer.

As described above, it may be useful to add crosslinking agents such asEGDMA, TEGDMA, or TMPTA, for example, to enhance the resulting polymer'sdimensional stability. It may also be advantageous to add ultraviolet(UV) absorbing compounds with the lens monomers prior to polymerizationfor incorporation into the resultant polymer. The UV absorber shouldpreferably be capable of polymerization into the lens matrix so as toresist extraction under physiologic conditions. The UV-absorbing monomercan be present in an amount effective to give the desired UV-absorbingproperties, generally less than 4 percent by weight of the polymer, suchas from 0.01 to about 1 percent by weight of the polymer.

Examples of specific polymers useful in the present invention areincluded in Table 1 which are also discussed in the examples where allweights used in the polymerization are shown in grams with thepercentage of the monomers in the polymer shown in parenthesis based onthe total of all monomers and crosslinking agents and assumingincorporation of all monomers and crosslinkers in the polymers.

TABLE 1 EOEMA HEMA EGDMA TMPTMA Initiator Water Examples (g (%)) (g (%))(g) (g) g Content (%) 1 92 (91.45) 8 (7.95) 0.1 0.5 0.07 3.6 2 90(89.46) 10 (9.94)  0.1 0.5 0.07 4.0 3 88 (87.48) 12 (11.93) 0.1 0.5 0.074.2 4 96 (95.43) 4 (3.98) 0.1 0.5 0.07 2.4 5 92 (91.45) 8 (7.95) 0.1 0.50.07 3.1 6 88 (87.48) 12 (11.93) 0.1 0.5 0.07 4.0 7 98 (96.84) 2 (1.98)0.2 1.0 0.07 2.3 8 96 (94.86) 4 (3.95) 0.2 1.0 0.07 2.4 9 92 (90.91) 8(7.91) 0.2 1.0 0.07 3.3 p-HEMA/ 25 75 0.13 max 0.5 25.0 EOEMA p-HEMA  099 38.0 p-EOEMA 99  0 1.5

These polymers are formed using the same procedures disclosed inExample 1. 2,2-Azobis (2,4-dimethylvaleronitrile) was used as aninitiator to prepare the polymers of each of Examples 1-9 in an amountof about 0.07 weight percent based on the total weight of the monomers.

Unfolding was measured at 36° C. for the examples in Table 1. Examples1-9 each unfolded at times of less than 150 seconds. The CT (centralthickness) for lenses formed from the polymers of Examples 1-9 rangedfrom 0.9 mm to 1.2 mm. The thickness of haptics formed from the polymerof each of Examples 1-9 ranged from 0.5 mm to 0.8 mm. The refractiveindex at 22° C. for the polymers of Examples 1-9 were 1.48.

Lenses formed from the polymers described in Table 1 do not developreadily observable bubbles or voids in the matrix when such lenses areplaced in a saline solution at 40° C. overnight and allowed to cool roomtemperature. Therefore, no glistening is observed for these lenses.Therefore, in some embodiments, lenses formed from the polymers of theinvention do not form bubbles when placed in a saline solution at 40° C.overnight and then cooled to room temperature.

Lenses formed from the polymers described in Table 1 also have veryfavorable unfolding properties. For example, lenses formed from thepolymers of Table 1 unfold in less than or about 2 minutes when placedin a saline solution at 37° C. The average thickness of these lenses isgenerally less than 1 mm such as lenses with a central thickness of from0.793 mm to 0.999 mm. In some embodiments, the lenses unfold in times ofless than 1 minute and in still other embodiments, they unfold in lessthan or about 30 seconds.

The polymers used in the intraocular lenses preferably have a refractiveindex (RI) of greater than or about 1.4 generally from about 1.4 toabout 1.5. An advantage of polymers of the present invention is thatthey can be folded prior to insertion, thereby reducing the size of theincision. The RI value of a material influences the design and theparameters of an intraocular lens. Hence, besides biocompatibility, anideal intraocular lens is foldable and injectable, and has the abilityto quickly regain its shape and optical quality after insertion, and hasa high RI value. The intraocular lenses of the present invention havebeen found to possess these desired characteristics. Furthermore, thehydrophobic nature of lenses formed from the polymers of the inventionprovides lenses that are more resistant to opacification. Thus, theintraocular lenses of the present invention fulfill the requirements ofa high performance intraocular lens and have excellent foldingcharacteristics, a relatively high refraction index, excellent unfoldingcharacteristics, and have improved opacification-resistance properties.

Initial results show that as the hydrophilic content increases, so doesthe stiffness (T_(g)) of the polymer. When cut into discs and hydrated,the materials show a wide range of flexibility that appears to varyinversely with the water content, at least within range of compositionsshown in Table 1. Initial studies indicate that the polymer compositionsof the invention possess useful and favorable thermal and mechanicalproperties.

The intraocular lenses of the present invention may be formed by methodsknown in the art. For example, in an exemplary process the monomers thatform the polymer are polymerized into a polymer rod, polymer blanks ordiscs are formed from the rod, and then the blanks are cut, for example,by a lathe into the intraocular lens. The rods can be made by aprocedure which begins with polymerizing, in a mold, such as in atubular or cylindrical mold, a mixture of initiator and monomers, toform an optically clear soft lens body. As discussed above, it may bedesirable to incorporate cross-linking materials andultraviolet-absorbing compounds during polymerization or into theresultant polymer matrix. In some embodiments the polymer rods are thencut and ground or otherwise machined, into blanks of the desireddiameter and thickness by lathe cutting and machine milled attemperatures below the T_(g) into an intraocular lens.

Generally, the composite material rod is lathe cut or ground to adiameter 0.5 to 2.0 mm thicker than the required distance from thecenter of the lens body to the furthest edge of the legs or haptics.This rod is then cut into blanks of uniform thickness. The blanks areground and lapped to a diameter and thickness suitable for lathe cuttingand machine milling in the conventional manner into the intraocular lensof the present invention. Because the present polymers may have lowglass transition temperatures, the rod or blanks may require coolingbelow T_(g) prior to and/or during cutting, lathing and/or milling.

A general description of a stepwise process for forming the blanks intointraocular lenses is set forth in the flow chart below. One havingordinary skill in the field of intraocular lens manufacturing, from areview of the present specification, can make intraocular lenses usingthe general knowledge in the art on intraocular lens manufacture and theprocess of cryogenic machining.

Intraocular lenses can also be made by molding the present polymer toform all or part of the optic portion of the lens. For example, thepresent polymer can be polymerized in a mold by a liquid mixture ofmonomers and additional components, to form an optically clear soft lensbody. These molding methods can involve molding the optics on one halfof the lens, such as the anterior or posterior portion, or fully moldingthe lens. When only half of the optic portion of the lens is formed inthe mold then the second side optics can be machined, for example asdiscussed above. In either of these embodiments, additional material canbe molded to allow machining of various haptic designs.

The invention is illustrated by the following non-limiting examples.

EXAMPLES

EOEMA refers to ethoxyethyl methacrylateHEMA refers to 2-hydroxyethyl methacrylateTMPTMA refers to trimethylol propane trimethacrylateEGDMA refers to ethylene glycol dimethacrylate

Example 1

Ethoxyethyl methacrylate (EOEMA) (92 g) was mixed with 8 grams of2-hydroxyethyl methacrylate (HEMA), 0.5 grams of trimethylol propanetrimethacrylate (TMPTMA) and 0.1 grams of ethylene glycol dimethacrylate(EGDMA) without solvent. The mixture was degassed while applyingvigorous stirring. The mixture was dispensed into cylindrical molds,polymerized at 30° C. for 15 to 30 hours, and post-cured at up to 100°C. for 5 hours. The polymer was then removed from the molds, thecylindrical molds were ground to 0.5 to 0.65 inches (1.27 to 1.65 cm.)in diameter, and formed into blanks. The mechanical formation processcomprised cutting the polymer into cylinders of 0.1 to 0.2 inches (0.25to 0.51 cm.) in thickness.

Procedures for Machining Polymers

Sample optics may be cut using a DAC lathe with a freezing or coolingdevice attached to the collet of a DAC-Vision lathe. The freezingapparatus allowed polymer blanks to be affixed to a steel mandrel usingmoisture/ice. Freezing served two purposes: 1) it cooled the acrylicrubber to below its T_(g) allowing for ease of cutting of the surfaceand 2) it allowed the icy surface to fix the blank in position forcutting. All materials will exhibit an optimal temperature for thisoperation which may vary as known by those skilled in the art, but willalways be below the T_(g) of the polymer. For examples 7 through 10, thefollowing conditions were used. The rough and fine tools consisted ofsingle point diamond tools 0.5 mm and 0.3 mm in radius, respectively.The blank surface temperature on the cooling device ranged from 5° C. to−5° C., and the DAC lathe run parameters used are listed in thefollowing table:

Rough Tool Fine Tool Spindle Speed 10,000 rpm 9,500 rpm Feed Rate 0.66in/min 0.33 in/min Depth of Cut 0.2 mm 0.07 mm

The present compositions can have any or all of the components describedherein. Likewise, the present methods can be carried out by performingany of the steps described herein, either alone or in variouscombinations. One skilled in the art will recognize that all embodimentsof the present invention are capable of use with all other appropriateembodiments of the invention described herein. Additionally, one skilledin the art will realize that the present invention also encompassesvariations of the present probes, configurations and methods thatspecifically exclude one or more of the components or steps describedherein.

The following is a list of non-limiting embodiments of optic portions ofan intraocular lens, in accordance with the present invention.

An optic portion of an intraocular lens, the optic portion comprising apolymer that comprises, consists of, or consists essentially of:

(a) one or more alkoxyalkyl methacrylate monomers and/or one or morealkoxyalkyl acrylate monomers that are incorporated in the polymer;(b) one or more hydroxyalkyl methacrylate monomers and/or one or morehydroxyalkyl acrylate monomers that are incorporated in the polymer; and(c) optionally, one or more crosslinking agents that are incorporated inthe polymer,wherein the total combined weight of the one or more alkoxyalkylmethacrylate monomers and the one or more alkoxyalkyl acrylate monomersranges from 75 percent to 99 percent based on the total weight of thedry polymer, and the total combined weight of the one or morehydroxyalkyl methacrylate monomers and the one or more hydroxyalkylacrylate monomers ranges from 1 percent to 25 percent based on the totalweight of the dry polymer.

An intraocular lens, wherein the intraocular lens comprises one or morehaptic portion and the optic portion of the preceding paragraph.

The intraocular lens of the preceding paragraph, wherein the opticportion and the one or more haptic portion are made of the same polymer.The intraocular lens of the preceding paragraph, wherein the opticportion and the one or more haptic portion are part of a one pieceintraocular lens. The intraocular lens of preceding paragraph, whereinthe optic portion and the one or more haptic portions are made ofdifferent materials. The intraocular lens of preceding paragraph,wherein the optic portion and the one or more haptic portions form amultiple piece intraocular lens. The intraocular lens of precedingparagraph, further comprising a polymer surrounding the optic portion,wherein the polymer surrounding the optic portion is not the same as thepolymer of the optic portion.

The optic portion or the intraocular lens of any embodiment described inthe two preceding paragraphs, wherein the one or more alkoxyalkylmethacrylate monomers have the formula R₁—O—R₂-MA prior to beingincorporated in the polymer, and the one or more alkoxyalkyl acrylatemonomers have the formula, R₃—O—R₄-A prior to being incorporated in thepolymer, wherein MA is methacrylate, A is acrylate, and R₁, R₂, R₃, andR₄ are independently selected from alkyl groups having from 1 to 5carbon atoms.

The optic portion or the intraocular lens of the preceding paragraph,wherein R₁ and R₃ have from 1 to 3 carbon atoms, and R₂ and R₄ have 2 or3 carbon atoms. The optic portion or the intraocular lens of thepreceding paragraph, wherein R₁ and R₃ have 2 carbon atoms, and R₂ andR₄ have 2 carbon atoms. The optic portion or the intraocular lens of thepreceding paragraph, wherein the polymer of the optic portion comprisesincorporated ethoxyethyl methacrylate. Regarding the immediatelypreceding embodiment, the total weight of the ethoxyethyl methacrylatemay range from 80 percent to 98 percent based on the total weight of thedry polymer of the optic portion, or from 86 percent to 98 percent basedon the total weight of the dry polymer of the optic portion.

The optic portion or the intraocular lens of any one of the preceding,non-limiting embodiments, wherein the one or more hydroxyalkylmethacrylate monomers have the formula HO—R₅-MA prior to beingincorporated in the polymer, and the one or more hydroxyalkyl acrylatemonomers have the formula, HO—R₆-A prior to being incorporated in thepolymer, wherein MA is methacrylate, A is acrylate, and R₅ and R₆ areindependently selected from alkyl groups having from 1 to 4 carbonatoms.

The optic portion or the intraocular lens of the preceding paragraph,wherein R₅ and R₆ have from 2 to 3 carbon atoms. The optic portion orthe intraocular lens of the preceding paragraph, wherein R₅ and R₆ have2 carbon atoms. The optic portion or the intraocular lens of thepreceding paragraph, wherein the polymer of the optic portion comprisesincorporated 2-hydroxyethyl methacrylate. Regarding the immediatelypreceding embodiment, the total weight of the 2-hydroxyethylmethacrylate may range from 1 percent to 20 percent based on the totalweight of the dry polymer of the optic portion, or from 1 percent to 12percent based on the total weight of the dry polymer of the opticportion.

The optic portion or the intraocular lens of any one of the precedingnon-limiting embodiments, wherein the polymer of the optic portioncomprises, the one or more crosslinking agents that are incorporated inthe polymer.

The optic portion or the intraocular lens of the preceding paragraph,wherein at least one of the one or more crosslinking agents is adi-functional crosslinking agent prior to incorporation in the polymer,and particularly, wherein the di-functional crosslinking agent isselected from ethylene glycol dimethacrylate prior to being incorporatedin the polymer or tetraethylene glycol dimethacrylate prior to beingincorporated in the polymer.

The optic portion or the intraocular lens of the preceding paragraph,wherein the polymer of the optic portion comprises incorporated ethyleneglycol dimethacrylate, and the total weight of the ethylene glycoldimethacrylate ranges from 0.05 percent to 0.5 percent based on thetotal weight of the dry polymer of the optic portion, or from 0.08percent to 0.25 percent based on the total weight of the dry polymer ofthe optic portion.

The optic portion or the intraocular lens of any one of the precedingthree paragraphs, wherein at least one of the one or more crosslinkingagents is a multi-functional crosslinking agent prior to incorporationin the polymer.

The optic portion or the intraocular lens of the preceding paragraph,wherein the multi-functional crosslinking agent is selected fromtrimethylol propane trimethacrylate or trimethylol propane triacrylateprior to being incorporated in the polymer.

The optic portion or the intraocular lens of the preceding paragraph,wherein the polymer of the optic portion comprises incorporatedtrimethylol propane trimethacrylate and/or trimethylol propanetriacrylate, and the total combined weight of the trimethylol propanetrimethacrylate and the trimethylol propane triacrylate ranges from 0.3percent to 1.5 percent based on the total weight of the dry polymer ofthe optic portion, or from 0.45 percent to 1.2 percent based on thetotal weight of the dry polymer of the optic portion, or from 0.5percent to 1.0 percent based on the total weight of the dry polymer ofthe optic portion.

The optic portion or the intraocular lens of any one of the precedingnon-limiting embodiments, wherein the polymer of the optic portionfurther comprises water.

The optic portion or the intraocular lens of any one of the preceding,non-limiting embodiments, wherein the polymer of the optic portionfurther comprises one or more ultraviolet absorbing compounds and/or oneor more ultraviolet absorbing monomer that is incorporated in thepolymer of optic portion.

An optic portion or an intraocular lens comprising a polymer thatcomprises, consists of, or consists essentially of:

(a) an incorporated alkoxyalkyl methacrylate in an amount of from 87percent to 98 percent by weight based on the total weight of the drypolymer;(b) an incorporated hydroxyalkyl methacrylate in an amount of from 1.5percent to 12 percent by weight based on the total weight of the drypolymer;(c) an incorporated di-functional methacrylate and/or di-functionalacrylate crosslinking agent in an amount ranging from 0.085 percent to0.2 percent based on the total weight of the dry polymer;(d) an incorporated multi-functional methacrylate and/or multifunctionalacrylate crosslinking agent in an amount ranging from 0.4 percent to 1percent based on the total weight of the dry polymer; and(e) optionally one or more additional ingredients selected from water, aultraviolet absorbing compound or monomer, a colorant, or anantioxidant.

The optic portion or the intraocular lens of the preceding paragraph,wherein the alkoxyalkyl methacrylate is ethoxyethyl methacrylate, thehydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate, thedi-functional methacrylate and/or acrylate crosslinking agent isethylene glycol dimethacrylate, and the multi-functional methacrylateand/or acrylate crosslinking agent is trimethylol propanetrimethacrylate.

The optic portion or the intraocular lens of any preceding non-limitingembodiment, wherein the glass transition temperature of the polymer ofthe optic portion is below about 35° C.

The optic portion or the intraocular lens of the preceding paragraph,wherein the glass transition temperature of the polymer of the opticportion is from about −25° C. to about 35° C., or from about −5° C. toabout 15° C.

The optic portion or the intraocular lens of any preceding, non-limitingembodiment, wherein the polymer of the optic portion has a refractiveindex of 1.40 or higher, or of 1.46 or higher, or of 1.48 or higher.

The optic portion or the intraocular lens of any preceding, non-limitingembodiment, wherein the polymer of the optic portion comprises water,and the equilibrium water content is less than or about 5 percent basedon the weight of the polymer after it is hydrated.

The optic portion or the intraocular lens of the preceding paragraph,wherein the equilibrium water content ranges from 2 percent to 4.5percent based on the weight of the polymer after it is hydrated, or from2.3 percent to 4.2 percent based on the weight of the polymer after itis hydrated.

The optic portion or the intraocular lens of any preceding, non-limitingembodiment wherein the polymer of the optic portion containssubstantially no aromatic polymer.

The following is a list of non-limiting embodiments of polymers, inaccordance with the present invention.

A polymer that comprises, consists of, or consists essentially of:

(a) one or more alkoxyalkyl methacrylate monomers and/or one or morealkoxyalkyl acrylate monomers that are incorporated in the polymer;(b) one or more hydroxyalkyl methacrylate monomers and/or one or morehydroxyalkyl acrylate monomers that are incorporated in the polymer; and(c) optionally, one or more crosslinking agents that are incorporated inthe polymer,wherein the total combined weight of the one or more alkoxyalkylmethacrylate monomers and the one or more alkoxyalkyl acrylate monomersranges from 75 percent to 99 percent based on the total weight of thedry polymer, and the total combined weight of the one or morehydroxyalkyl methacrylate monomers and the one or more hydroxyalkylacrylate monomers ranges from 1 percent to 25 percent based on the totalweight of the dry polymer.

The polymer of the preceding paragraph, wherein the one or morealkoxyalkyl methacrylate monomers have the formula R₁—O—R₂-MA prior tobeing incorporated in the polymer, and the one or more alkoxyalkylacrylate monomers have the formula, R₃—O—R₄-A prior to beingincorporated in the polymer, wherein MA is methacrylate, A is acrylate,and R₁, R₂, R₃, and R₄ are independently selected from alkyl groupshaving from 1 to 5 carbon atoms.

The polymer of the preceding paragraph, wherein R₁ and R₃ have from 1 to3 carbon atoms, and R₂ and R₄ have 2 or 3 carbon atoms. The polymer ofthe preceding paragraph, wherein R₁ and R₃ have 2 carbon atoms, and R₂and R₄ have 2 carbon atoms. The polymer of the preceding paragraph,wherein the polymer comprises incorporated ethoxyethyl methacrylate, andparticularly wherein the total weight of the ethoxyethyl methacrylateranges from 80 percent to 98 percent based on the total weight of thedry polymer, or from 86 percent to 98 percent based on the total weightof the dry polymer.

The polymer of any preceding, non-limiting embodiment, wherein the oneor more hydroxyalkyl methacrylate monomers have the formula HO—R₅-MAprior to being incorporated in the polymer, and the one or morehydroxyalkyl acrylate monomers have the formula, HO—R₆-A prior to beingincorporated in the polymer, wherein MA is methacrylate, A is acrylate,and R₅ and R₆ are independently selected from alkyl groups having from 1to 4 carbon atoms.

The polymer of the preceding paragraph, wherein R₅ and R₆ have from 2 to3 carbon atoms. The polymer of the preceding paragraph, wherein R₅ andR₆ have 2 carbon atoms. The polymer of the preceding paragraph, whereinthe polymer comprises incorporated 2-hydroxyethyl methacrylate, andparticularly wherein the total weight of the 2-hydroxyethyl methacrylateranges from 1 percent to 20 percent based on the total weight of the drypolymer, or from 1 percent to 12 percent based on the total weight ofthe dry polymer.

The polymer of any preceding, non-limiting embodiment, wherein thepolymer comprises, the one or more crosslinking agents that areincorporated in the polymer.

The polymer of the preceding paragraph, wherein the one or morecrosslinking agents include a di-functional crosslinking agent isselected from ethylene glycol dimethacrylate prior to being incorporatedin the polymer or tetraethylene glycol dimethacrylate prior to beingincorporated in the polymer.

The polymer of the preceding paragraph, wherein the polymer comprisesincorporated ethylene glycol dimethacrylate, and the total weight of theethylene glycol dimethacrylate ranges from 0.05 percent to 0.5 percentbased on the total weight of the dry polymer, or from 0.08 percent to0.25 percent based on the total weight of the dry polymer, or from 0.1percent to 0.2 percent based on the total weight of the dry polymer.

The polymer of any one of the three preceding paragraphs, wherein atleast one of the one or more crosslinking agents is a multi-functionalcrosslinking agent prior to incorporation in the polymer.

The polymer of the preceding paragraph, wherein the multi-functionalcrosslinking agent is selected from trimethylol propane trimethacrylateor trimethylol propane triacrylate prior to being incorporated in thepolymer.

The polymer of the preceding paragraph, wherein the polymer comprisesincorporated trimethylol propane trimethacrylate and/or trimethylolpropane triacrylate, and the total combined weight of the trimethylolpropane trimethacrylate and the trimethylol propane triacrylate rangesfrom 0.3 percent to 1.5 percent based on the total weight of the drypolymer, or from 0.45 percent to 1.2 percent based on the total weightof the dry polymer, or from 0.5 percent to 1.0 percent based on thetotal weight of the dry polymer.

The polymer of any preceding, non-limiting embodiment, wherein thepolymer further comprises water.

The polymer of any preceding, non-limiting embodiment, wherein thepolymer of the further comprises one or more ultraviolet absorbingcompounds and/or one or more ultraviolet absorbing monomer that isincorporated in the polymer of optic portion.

A polymer that comprises, consists of, or consists essentially of:

(a) an incorporated alkoxyalkyl methacrylate in an amount of from 87percent to 98 percent by weight based on the total weight of the drypolymer;(b) an incorporated hydroxyalkyl methacrylate in an amount of from 1.5percent to 12 percent by weight based on the total weight of the drypolymer;(c) an incorporated di-functional methacrylate and/or di-functionalacrylate crosslinking agent in an amount ranging from 0.085 percent to0.2 percent based on the total weight of the dry polymer;(d) an incorporated multi-functional methacrylate and/or multifunctionalacrylate crosslinking agent in an amount ranging from 0.4 percent to 1percent based on the total weight of the dry polymer; and(e) optionally one or more additional ingredients selected from water, aultraviolet absorbing compound or monomer, a colorant, or anantioxidant.

The polymer of the preceding paragraph, wherein the alkoxyalkylmethacrylate is ethoxyethyl methacrylate, the hydroxyalkyl methacrylateis 2-hydroxyethyl methacrylate, the di-functional methacrylate and/oracrylate crosslinking agent is ethylene glycol dimethacrylate, and themulti-functional methacrylate and/or acrylate crosslinking agent istrimethylol propane trimethacrylate.

The polymer of any preceding non-limiting embodiment, wherein thepolymer comprises water, and the equilibrium water content is less thanor about 5 percent based on the weight of the polymer after it ishydrated, or from 2 percent to 4.5 percent based on the weight of thepolymer after it is hydrated, or from 2.3 percent to 4.2 percent basedon the weight of the polymer after it is hydrated.

The polymer of any one of the preceding, non-limiting embodiments,wherein the polymer contains substantially no aromatic polymer.

The following is a list of non-limiting embodiments of methods formanufacturing a polymer, in accordance with the present invention.

A method for manufacturing a polymer, comprising:

(a) polymerizing a mixture to form the polymer, wherein the mixturecomprises, consists of, or consists essentially of:

(i) one or more alkoxyalkyl methacrylate monomers and/or one or morealkoxyalkyl acrylate monomers;

(ii) one or more hydroxyalkyl methacrylate monomers and/or one or morehydroxyalkyl acrylate monomers;

(iii) optionally, one or more crosslinking agents; and

(iv) optionally, one or more initiator,

wherein the total combined weight of the one or more alkoxyalkylmethacrylate monomers and the one or more alkoxyalkyl acrylate monomersin the mixture ranges from 75 percent to 99 percent based on the totalcombined weight of the one or more alkoxyalkyl methacrylate monomers,the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture, and the total combined weight of the one or more hydroxyalkylmethacrylate monomers and the one or more hydroxyalkyl acrylate monomersin the mixture ranges from 1 percent to 25 percent based on the totalcombined weight of the one or more alkoxyalkyl methacrylate monomers,the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture.

The method for manufacturing the polymer of the preceding paragraph,wherein the mixture is polymerized in a mold and, optionally, furthercomprising forming an intraocular lens from the polymer. The method formanufacturing the polymer of the preceding paragraph, further comprisingforming an optic portion of an intraocular lens from the polymer, andoptionally, further comprising forming an intraocular lens from theoptic portion.

The method for manufacturing the polymer of any one of the preceding,non-limiting embodiments, wherein the one or more alkoxyalkylmethacrylate monomers have the formula R₁, —O—R₂-MA, and the one or morealkoxyalkyl acrylate monomers have the formula, R₃—O—R₄-A, wherein MA ismethacrylate, A is acrylate, and R₁, R₂, R₃, and R₄ are independentlyselected from alkyl groups having from 1 to 5 carbon atoms.

The method for manufacturing the polymer of the preceding paragraph,wherein R₁ and R₃ have from 1 to 3 carbon atoms, and R₂ and R₄ have 2 or3 carton atoms. The method for manufacturing the polymer of thepreceding paragraph, wherein R₁ and R₃ have 2 carbon atoms, and R₂ andR₄ have 2 carbon atoms. The method for manufacturing the polymer of thepreceding paragraph, wherein the mixture comprises ethoxyethylmethacrylate, and particularly wherein the total weight of theethoxyethyl methacrylate in the mixture ranges from 80 percent to 98percent (or from 86 percent to 98 percent) based on the total combinedweight of the one or more alkoxyalkyl methacrylate monomers, the one ormore alkoxyalkyl acrylate monomers, the one or more hydroxyalkylmethacrylate monomers, the one or more hydroxyalkyl acrylate monomers,and the one or more crosslinking agents in the mixture, or

The method for manufacturing the polymer of any preceding, non-limitingembodiment, wherein the one or more hydroxyalkyl methacrylate monomershave the formula HO—R₅-MA, and the one or more hydroxyalkyl acrylatemonomers have the formula, HO—R₆-A, wherein MA is methacrylate, A isacrylate, and R₅ and R₆ are independently selected from alkyl groupshaving from 1 to 4 carbon atoms.

The method for manufacturing the polymer of the preceding paragraph,wherein R₅ and R₆ have from 2 to 3 carbon atoms. The method formanufacturing the polymer of the preceding paragraph, wherein R₅ and R₆have 2 carbon atoms. The method for manufacturing the polymer of thepreceding paragraph, wherein the mixture comprises 2-hydroxyethylmethacrylate, particularly wherein the total weight of the2-hydroxyethyl methacrylate in the mixture ranges from 1 percent to 12percent based on the total combined weight of the one or morealkoxyalkyl methacrylate monomers, the one or more alkoxyalkyl acrylatemonomers, the one or more hydroxyalkyl methacrylate monomers, the one ormore hydroxyalkyl acrylate monomers, and the one or more crosslinkingagents in the mixture.

The method for manufacturing the polymer of any preceding, non-limitingembodiment, wherein the mixture comprises, the one or more crosslinkingagents.

The method for manufacturing the polymer of the preceding paragraph,wherein at least one of the one or more crosslinking agents is adi-functional crosslinking agent.

The method for manufacturing the polymer of the preceding paragraph,wherein the di-functional crosslinking agent is selected from ethyleneglycol dimethacrylate or tetraethylene glycol dimethacrylate.

The method for manufacturing the polymer of the preceding paragraph,wherein the di-functional crosslinking agent comprises ethylene glycoldimethacrylate, and the total weight of the ethylene glycoldimethacrylate in the mixture ranges from 0.05 percent to 0.5 percent(or from 0.08 percent to 0.25 percent, or from 0.1 percent to 0.2percent) based on the total combined weight of the one or morealkoxyalkyl methacrylate monomers, the one or more alkoxyalkyl acrylatemonomers, the one or more hydroxyalkyl methacrylate monomers, the one ormore hydroxyalkyl acrylate monomers, and the one or more crosslinkingagents in the mixture.

The method for manufacturing the polymer of any preceding, non-limitingembodiment, wherein at least one of the one or more crosslinking agentsis a multi-functional crosslinking agent.

The method for manufacturing the polymer of the preceding paragraph,wherein the multi-functional crosslinking agent is selected fromtrimethylol propane trimethacrylate or trimethylol propane triacrylate.

The method for manufacturing the polymer of the preceding paragraph,wherein the crosslinking agent comprises trimethylol propanetrimethacrylate and/or trimethylol propane triacrylate, and the totalcombined weight of the trimethylol propane trimethacrylate and thetrimethylol propane triacrylate in the mixture ranges from 0.3 percentto 1.5 percent (or from 0.45 percent to 1.2 percent or from 0.5 percentto 1.0 percent) based on the total combined weight of the one or morealkoxyalkyl methacrylate monomers, the one or more alkoxyalkyl acrylatemonomers, the one or more hydroxyalkyl methacrylate monomers, the one ormore hydroxyalkyl acrylate monomers, and the one or more crosslinkingagents in the mixture.

The method for manufacturing the polymer of any preceding, non-limitingembodiment, wherein the mixture further comprises one or moreultraviolet absorbing compounds and/or one or more ultraviolet absorbingmonomer.

The method for manufacturing the polymer from a mixture that comprises,consists of, or consists essentially of:

(a) an alkoxyalkyl methacrylate, wherein the alkoxyalkyl methacrylate ispresent in the mixture in an amount of from 87 percent to 98 percent byweight based on the total combined weight of the one or more alkoxyalkylmethacrylate monomers, the one or more alkoxyalkyl acrylate monomers,the one or more hydroxyalkyl methacrylate monomers, the one or morehydroxyalkyl acrylate monomers, and the one or more crosslinking agentsin the mixture;(b) a hydroxyalkyl methacrylate, wherein the hydroxyalkyl methacrylateis present in the mixture in an amount of from 1.5 percent to 12 percentby weight based on the total combined weight of the one or morealkoxyalkyl methacrylate monomers, the one or more alkoxyalkyl acrylatemonomers, the one or more hydroxyalkyl methacrylate monomers, the one ormore hydroxyalkyl acrylate monomers, and the one or more crosslinkingagents in the mixture;(c) a di-functional methacrylate and/or di-functional acrylatecrosslinking agent, wherein the combined weight of the di-functionalmethacrylate and/or the di-functional acrylate crosslinking agent in themixture ranges from 0.085 percent to 0.2 percent based on the totalcombined weight of the one or more alkoxyalkyl methacrylate monomers,the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture;(d) a multi-functional methacrylate and/or multifunctional acrylatecrosslinking agent, wherein the combined weight of the multi-functionalmethacrylate and/or the multi-functional acrylate crosslinking agent inthe mixture ranges from 0.4 percent to 1 percent based on the totalcombined weight of the one or more alkoxyalkyl methacrylate monomers,the one or more alkoxyalkyl acrylate monomers, the one or morehydroxyalkyl methacrylate monomers, the one or more hydroxyalkylacrylate monomers, and the one or more crosslinking agents in themixture; and(e) optionally one or more additional ingredients selected from aninitiator, an ultraviolet absorbing compound or monomer, a colorant, oran antioxidant.

The method for manufacturing the polymer of the preceding paragraph,wherein the alkoxyalkyl methacrylate is ethoxyethyl methacrylate, thehydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate, thedi-functional methacrylate and/or acrylate crosslinking agent isethylene glycol dimethacrylate, and the multi-functional methacrylateand/or acrylate crosslinking agent is trimethylol propanetrimethacrylate.

The method for manufacturing the polymer of any one of the precedingnon-limiting embodiments, wherein the equilibrium water content is lessthan or about 5 percent based on the weight of the polymer after it ishydrated.

The method for manufacturing the polymer of the preceding paragraph,wherein the equilibrium water content ranges from 2 percent to 4.5percent based on the weight of the polymer after it is hydrated. Themethod for manufacturing the polymer of the preceding paragraph, whereinthe equilibrium water content ranges from 2.3 percent to 4.2 percentbased on the weight of the polymer after it is hydrated.

The method for manufacturing the polymer of any preceding, non-limitingembodiment, wherein the mixture contains substantially no aromaticpolymer. The method of any preceding, non-limiting embodiment, whereinthe mixture comprises less than 2 percent by weight of any aromaticcomponent.

A method for modifying an individual's eyesight, comprising insertingthe intraocular lens or the intraocular lens made from the optic portionof any preceding, non-limiting embodiment into an eye of a subject.

The method for modifying an individual's eyesight of the precedingparagraph, further comprising folding the intraocular lens prior toinserting the intraocular lens into the eye and allowing the intraocularlens to unfold after it is inserted into the eye of the subject.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” “more than”and the like include the number recited and refer to ranges which can besubsequently broken down into subranges as discussed above. In the samemanner, all ratios disclosed herein also include all subratios fallingwithin the broader ratio.

One skilled in the art will also readily recognize that where membersare grouped together in a common manner, such as in a Markush group, thepresent invention encompasses not only the entire group listed as awhole, but each member of the group individually and all possiblesubgroups of the main group. Accordingly, for all purposes, the presentinvention encompasses not only the main group, but also the main groupabsent one or more of the group members. The present invention alsoenvisages the explicit exclusion of one or more of any of the groupmembers in the claimed invention.

All references, patents, and publications disclosed herein arespecifically incorporated by reference in their entireties and for allpurposes as if fully set forth in their entireties. Unless otherwisespecified, “a” or “an” means “one or more”.

While preferred embodiments have been illustrated and described, itshould be understood that changes and modifications can be made thereinin accordance with ordinary skill in the art without departing from theinvention in its broader aspects as defined in the following claims.

1. A polymer that comprises: (a) one or more alkoxyalkyl methacrylatemonomers and/or one or more alkoxyalkyl acrylate monomers that areincorporated in the polymer; (b) one or more hydroxyalkyl methacrylatemonomers and/or one or more hydroxyalkyl acrylate monomers that areincorporated in the polymer; and (c) optionally, one or morecrosslinking agents that are incorporated in the polymer, wherein thetotal combined weight of the one or more alkoxyalkyl methacrylatemonomers and the one or more alkoxyalkyl acrylate monomers ranges from75 percent to 99 percent based on the total weight of the dry polymer,and the total combined weight of the one or more hydroxyalkylmethacrylate monomers and the one or more hydroxyalkyl acrylate monomersranges from 1 percent to 25 percent based on the total weight of the drypolymer.
 2. The polymer of claim 1, wherein the one or more alkoxyalkylmethacrylate monomers have the formula R₁—O—R₂-MA prior to beingincorporated in the polymer, and the one or more alkoxyalkyl acrylatemonomers have the formula, R₃—O—R₄-A prior to being incorporated in thepolymer, wherein MA is methacrylate, A is acrylate, and R₁, R₂, R₃, andR₄ are independently selected from alkyl groups having from 1 to 5carbon atoms.
 3. The polymer of claim 2, wherein R₁ and R₃ have 2 carbonatoms, and R₂ and R₄, have 2 carbon atoms.
 4. The polymer of claim 2,wherein the polymer comprises incorporated ethoxyethyl methacrylate. 5.The polymer of claim 4, wherein the polymer comprises incorporatedethoxyethyl methacrylate, and the total weight of the ethoxyethylmethacrylate ranges from 80 percent to 98 percent based on the totalweight of the dry polymer.
 6. The polymer of claim 1, wherein the one ormore hydroxyalkyl methacrylate monomers have the formula HO—R₅-MA priorto being incorporated in the polymer, and the one or more hydroxyalkylacrylate monomers have the formula, HO—R₆-A prior to being incorporatedin the polymer, wherein MA is methacrylate, A is acrylate, and R₅ and R₆are independently selected from alkyl groups having from 1 to 4 carbonatoms.
 7. The polymer of claim 6, wherein the polymer comprisesincorporated 2-hydroxyethyl methacrylate.
 8. The polymer of claim 7,wherein the polymer comprises incorporated 2-hydroxyethyl methacrylate,and the total weight of the 2-hydroxyethyl methacrylate ranges from 1percent to 20 percent based on the total weight of the dry polymer. 9.The polymer of claim 1, wherein the polymer comprises, the one or morecrosslinking agents that are incorporated in the polymer.
 10. Thepolymer of claim 9, wherein the crosslinking agent is selected fromethylene glycol dimethacrylate prior to being incorporated in thepolymer, or tetraethylene glycol dimethacrylate prior to beingincorporated in the polymer, trimethylol propane trimethacrylate priorto being incorporated in the polymer, and trimethylol propane tricrylateprior to being incorporated into the polymer.
 11. The polymer of claim1, wherein the polymer further comprises one or more ultravioletabsorbing compounds and/or one or more ultraviolet absorbing monomerthat is incorporated in the polymer.
 12. The polymer of claim 1, whereinthe polymer comprises: (a) an incorporated alkoxyalkyl methacrylate inan amount of from 87 percent to 98 percent by weight based on the totalweight of the dry polymer; (b) an incorporated hydroxyalkyl methacrylatein an amount of from 1.5 percent to 12 percent by weight based on thetotal weight of the dry polymer; (c) an incorporated di-functionalmethacrylate and/or di-functional acrylate crosslinking agent in anamount ranging from 0.085 percent to 0.2 percent based on the totalweight of the dry polymer; (d) an incorporated multi-functionalmethacrylate and/or multifunctional acrylate crosslinking agent in anamount ranging from 0.4 percent to 1 percent based on the total weightof the dry polymer; and (e) optionally one or more additionalingredients selected from water, a ultraviolet absorbing compound ormonomer, a colorant, or an antioxidant.
 13. The polymer of claim 12,wherein the alkoxyalkyl methacrylate is ethoxyethyl methacrylate, thehydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate, thedi-functional methacrylate and/or acrylate crosslinking agent isethylene glycol dimethacrylate, and the multi-functional methacrylateand/or acrylate crosslinking agent is trimethylol propanetrimethacrylate.
 14. The polymer of claims 1, wherein the polymercomprises water, and the equilibrium water content is less than or about5 percent based on the weight of the polymer after it is hydrated. 15.The polymer of claim 1, wherein the polymer contains substantially noaromatic polymer. 16-34. (canceled)